Keith, I have had a look at Emil Hartman's 1980 patent (US4215330)
================================================ http://l2.espacenet.com/dips/bnsviewer?CY=ch&LG= fr&DB=EPD&PN=US4215330&ID=US+++4215330A1+I+ ================================================ and it appears from the drawing that instead of a pair of solid magnets Hartman used a series of small individual magnets. Now if you want to close the loop then the way to go would be to build a SMOT with many individual magnets forming a slight but definite curve. Two such curved SMOTS would prove the principle and give one the confidence to build the rest. As to where the energy comes from - presumably it comes from a very slight weakening of the magnetic field for each ascent of the ball. This would explain why for that apparatus which was mentioned in an earlier post in some museum or other, the thing stopped working after some given interval and the owner had to take it away to "recharge" the "permanent" magnets. Reminds me of the thread on absolute temperature. ;-) Permanent - but not permanently Permanent. Absolute - but not absolutely Absolute. If the above analysis is correct, SMOT may not be a source of energy but it would make a wonderful executive toy. 8-) Cheers, Frank Grimer
